For future generations, an analogy:
HWPs on the geoscape are like the money on your cash account.
You also cannot say anything about that money... only how much you have.
Battlescape generator is like the ATM, from which you withdraw the money as individual objects (coins and notes).
Suddenly your money exists as objects, with color, weight, size, texture, material damage, width, length, height, nominal value, currency symbol, some president's picture, etc.
Debriefing is like putting the money back into the bank.
You don't have anymore those nice 5 copper coins and 7 different plastic notes, you just have a number (e.g. 423 dollars).